Vibrating piece, vibrator, oscillator, and electronic device

Abstract

A vibrating piece in which a CI values ratio is maintained constant while minimizing the CI value of the fundamental wave, variations of the CI values between the vibrating piece devices are reduced even if the base is made short, and the entire vibrating piece can be made smaller.

1. A vibrator having a vibrating piece housed in a package, said vibrating piece comprising: a base; and a vibration arm section formed so as to protrude from this base, a grooved portion being formed in at least one of the obverse surface and the rear surface of said vibration arm section, wherein a cut section is formed in said base, and an electrode section is formed in a part of said grooved portion. 
   
   
     2. A vibrator according to  claim 1 , wherein a grooved portion is formed in at least one of the obverse surface and the rear surface of said vibration arm section, and an electrode section is formed in a part of said grooved portion so that the CI (crystal impedance) value ratio of said vibrating piece (CI value of the harmonic wave/CI value of the fundamental wave) becomes 1.0 or more. 
   
   
     3. A vibrator according to  claim 2 , wherein the length of the electrode section formed in a part of said grooved portion of said vibration arm section along the longitudinal direction is formed to be approximately 45% to approximately 55% with respect to the length of said vibration arm section. 
   
   
     4. A vibrator according to  claim 1 , wherein said electrode section is an excitation electrode. 
   
   
     5. A vibrator according to  claim 1 , wherein a fixation area for fixing the vibrating piece is provided in said base, and said cut section is provided in the base between the fixation area and said vibration arm section. 
   
   
     6. A vibrator according to  claim 1 , wherein said vibrating piece is a tuning-fork vibrating piece formed by a crystal which oscillates at approximately 30 kHz to approximately 40 kHz. 
   
   
     7. A vibrator according to  claim 1 , wherein said package is formed in a box shape. 
   
   
     8. A vibrator according to  claim 1 , wherein said package is formed in a commonly-called cylinder type.